kross

A simple CLI to "multi-arch all the things"

What is kross ?

kross is a tool to automate the build of Docker images for multiple architectures without any changes required on your code

Quick start

• Install via pip

pip install kross

• Initialize it (once)

kross init

• Update your docker build commands

Before

docker build -t me/myapp:vX.X.X ...args... path/to/docker/context
docker push me/myapp:vX.X.X

After

kross build -t me/myapp:vX.X.X ...args... path/to/docker/context
kross push me/myapp:vX.X.X

Why kross ?

Kross is born from a Raspberry Pi passionnate developer. Because Raspberry Pi are arm-based and 90% of images on Dockerhub are amd64-based, developers have to duplicate/tweak all Dockerfiles so the image will work on it and avoid the too much popular cannot execute binary file: Exec format error.

To know more, read the full article.

How kross is working ?

kross is based upon the qemu library to build multiple architectures images on a amd64-based host machine. After all images are built and pushed to a docker registry, a manifest list is pushed too so that users can pull images based on their architectures in a seamless way.

Supported architectures

kross will try to build images for the following architectures:

• amd64
• arm32v6
• arm32v7
• arm64v8
• ppc64le
• s390x
• i386

Run the example

• Install kross pip install kross

• Check your machine configuration kross init

• Run the kross build kross build -t kross-world:v0.1.0 https://raw.githubusercontent.com/pcorbel/kross/master/docs/example/Dockerfile

• Run the kross push kross push kross-world:v0.1.0

• Check images availability on your Dockerhub account

• Run your image anywhere

docker run --rm kross-world:v0.1.0

Example image available here

Tips and tricks

To know exactly what is happening while kross is working export KROSS_VERBOSE=true